ST. GEORGE — Something special is taking place across the heavens this month, a spectacle known as the “Christmas Star” that will appear just a few days before the holiday.
The Christmas Star is actually a dynamic planetary conjunction that can easily be seen in the evening sky over the next two weeks. Jupiter and Saturn will move closer to one another — which will culminate in an astronomical spectacle on the night of Dec. 21, the winter solstice.
Such an event, dubbed the “Jupiter-Saturn Great Conjunction,” occurs every 20 years. The last time this happened was in 2000, but that event paled in comparison to what is taking place this year since the planets did not appear as close together then.
It has also been referred to as the “Star of Bethlehem” due to its brightness, similar to the star that is said to have guided the three wise men to Bethlehem.
Throughout the month of December, the planets will appear to draw ever closer each night. In Southern Utah, the pair will be easy to see with the naked eye by looking low in the southwest sky about 45 minutes after sunset. Jupiter will be the bright spot and Saturn will appear dimmer.
Jupiter and Saturn will come so close together in the western sky that they appear as one bright point of light when viewed with the naked eye. Though the planets will appear to overlap, Saturn and Jupiter won’t literally be close to each other, as both are massive planets — each roughly 760-1,300 times the size of Earth — and will still be hundreds of millions of miles apart.
At the closest point of alignment, Jupiter and Saturn will appear just a tenth of a degree apart for a single night, Dec. 21, and will appear so close it would only take a pinkie finger held at arm’s length to cover both planets.
A video with footage courtesy of NASA can be viewed at the top of this report.
Even though the great conjunction takes place on a single day, both planets “are already very close and they’ll remain unusually close through the end of the year,” according to the Stellar Vista Observatory’s Sky Report.
The planets appear close together because of their orbits, paths that are not a perfect circle. So when both planets and the Earth reach a certain point on their journey, the alignment makes them appear close together when viewed from Earth.
The sky report also says that Jupiter orbits faster than Saturn because it is closer to the Sun, which brings them to the same direction in the sky as seen from Earth. What makes this year’s alignment so incredible is the distance of separation between the planets at the point of conjunction and that the close encounter is taking place Dec. 21, which hasn’t happened since 1623. But even in 1623, it would have been nearly impossible to see since it was outshined by the setting sun.
John Mosley told St. George news that according to his calculations, it would have been extremely hard to see, if they could have seen it at all, although astronomers would have calculated what was happening.
The conjunction would have been much different 400 years earlier when the position of the two gas giants would have seemingly converged into a bright star across the dark night sky on Dec. 21, 1226, according to Astronomy.com.
The Christmas Star — aka the Star of Bethlehem
For centuries, scientists and scholars have debated the nature of this biblical light. It has been said that one possible explanation for the Star of Bethlehem is the three-times passing of Jupiter and Saturn between May and December in 7 BC, which was deemed a rare triple conjunction and would have created quite a spectacle.
But whether it was enough to send three wise men on a journey of hundreds of miles through deserts, mountains and arid terrain to see what was going on in Bethlehem seems unlikely, according to Phys.org.
Moreover, the conjunction that took place then was not nearly as bright as what will take place this year, and there are many other contributing factors to the age-old account of the events that took place on that starry night more than 20 centuries ago.
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